Feature/copy paste

CHANGES.md

@@ -3,6 +3,7 @@
 ### Version 3.1.0 - TBD ([javadoc](http://diffplug.github.io/durian-swt/javadoc/snapshot/), [snapshot](https://oss.sonatype.org/content/repositories/snapshots/com/diffplug/durian/durian-swt/))
 
 - `Shells` now detects the monitor using the center of the proposed bounds, rather than the top-left.
+- Added `StructuredDrag.copyToClipboard()` and `StructuredDrop.pasteFromClipboard()` [(#2)](https://github.com/diffplug/durian-swt/pull/2).
 
 ### Version 3.0.0 - August 1st 2018 ([javadoc](http://diffplug.github.io/durian-swt/javadoc/3.0.0/), [jcenter](https://bintray.com/diffplug/opensource/durian-swt/3.0.0/view))
 

durian-swt/src/main/java/com/diffplug/common/swt/dnd/CustomLocalTransfer.java

@@ -43,23 +43,30 @@ protected String[] getTypeNames() {
 		return new String[]{TYPE_NAME};
 	}
 
+	@SuppressWarnings("unchecked")
 	@Override
 	public void javaToNative(Object object, TransferData transferData) {
+		if (object != null) {
+			set((T) object);
+		}
 		byte[] check = TYPE_NAME.getBytes(StandardCharsets.UTF_8);
 		super.javaToNative(check, transferData);
 	}
 
 	@Override
 	public Object nativeToJava(TransferData transferData) {
-		Object result = super.nativeToJava(transferData);
-
-		// check result
-		Preconditions.checkArgument(result instanceof byte[], "%s should have been byte[]", result.getClass());
-		String resultStr = new String((byte[]) result, StandardCharsets.UTF_8);
-		Preconditions.checkArgument(TYPE_NAME.equals(resultStr), "%s should have been %s", resultStr, TYPE_NAME);
-
-		// return this transfer object itself
-		return this;
+		if (obj == null) {
+			return null;
+		} else {
+			// check result
+			Object result = super.nativeToJava(transferData);
+			Preconditions.checkArgument(result instanceof byte[], "%s should have been byte[]", result.getClass());
+			String resultStr = new String((byte[]) result, StandardCharsets.UTF_8);
+			Preconditions.checkArgument(TYPE_NAME.equals(resultStr), "%s should have been %s", resultStr, TYPE_NAME);
+
+			// return this transfer object itself
+			return get();
+		}
 	}
 
 	@Override

durian-swt/src/main/java/com/diffplug/common/swt/dnd/StructuredDrag.java

@@ -27,6 +27,7 @@
 
 import javax.annotation.Nullable;
 
+import org.eclipse.swt.dnd.Clipboard;
 import org.eclipse.swt.dnd.DND;
 import org.eclipse.swt.dnd.DragSource;
 import org.eclipse.swt.dnd.DragSourceEvent;
@@ -42,6 +43,7 @@
 import com.diffplug.common.collect.ImmutableMap;
 import com.diffplug.common.rx.RxBox;
 import com.diffplug.common.rx.RxGetter;
+import com.diffplug.common.swt.SwtMisc;
 
 /**
  * Typed mechanism for implementing drag listeners.
@@ -55,7 +57,8 @@ public enum DropResult {
 
 	@FunctionalInterface
 	public interface TypedDragHandler<T> {
-		T dragStartData(DragSourceEvent e);
+		/** DragSourceEvent will be null if it's starting from a 'Ctrl+C' copy. */
+		T dragStartData(@Nullable DragSourceEvent e);
 
 		default void dropped(DragSourceEvent e, T value, DropResult result) {}
 
@@ -246,13 +249,29 @@ public Listener(RxBox<Boolean> dragInProgress, ImmutableMap<Transfer, Handler> m
 			transfers = map.keySet().toArray(new Transfer[map.size()]);
 		}
 
+		public void copyToClipboard() {
+			Clipboard clipboard = new Clipboard(SwtMisc.assertUI());
+			try {
+				populateData(null);
+				Object[] dataPer = new Object[data.size()];
+				Transfer[] transferPer = new Transfer[data.size()];
+				int i = 0;
+				for (Map.Entry<Transfer, Object> entry : data.entrySet()) {
+					dataPer[i] = entry.getValue();
+					transferPer[i] = entry.getKey();
+					++i;
+				}
+				clipboard.setContents(dataPer, transferPer);
+			} finally {
+				clipboard.dispose();
+			}
+		}
+
 		public Transfer[] transferArray() {
 			return Arrays.copyOf(transfers, transfers.length);
 		}
 
-		@Override
-		public void dragStart(DragSourceEvent event) {
-			dragInProgress.set(true);
+		private void populateData(@Nullable DragSourceEvent event) {
 			data.clear();
 			handlers.forEach((transfer, handler) -> {
 				// get the drag data
@@ -261,6 +280,12 @@ public void dragStart(DragSourceEvent event) {
 					data.put(transfer, value);
 				}
 			});
+		}
+
+		@Override
+		public void dragStart(DragSourceEvent event) {
+			dragInProgress.set(true);
+			populateData(event);
 			event.doit = data.size() > 0;
 			if (event.doit) {
 				Transfer[] validTransfers = data.keySet().stream().toArray(Transfer[]::new);

durian-swt/src/main/java/com/diffplug/common/swt/dnd/StructuredDrop.java

@@ -27,6 +27,9 @@
 import java.util.function.Function;
 import java.util.function.Predicate;
 
+import javax.annotation.Nullable;
+
+import org.eclipse.swt.dnd.Clipboard;
 import org.eclipse.swt.dnd.DND;
 import org.eclipse.swt.dnd.DropTarget;
 import org.eclipse.swt.dnd.DropTargetEvent;
@@ -40,6 +43,7 @@
 import com.diffplug.common.base.Predicates;
 import com.diffplug.common.collect.ImmutableList;
 import com.diffplug.common.collect.ImmutableMap;
+import com.diffplug.common.swt.SwtMisc;
 
 /**
  * Typed mechanism for implementing drop listeners.
@@ -53,7 +57,8 @@ public enum DropMethod {
 
 	@FunctionalInterface
 	public interface TypedDropHandler<T> {
-		void onEvent(DropMethod method, DropTargetEvent e, T value);
+		/** If it's the result of a "paste", then DropTargetEvent will be null. */
+		void onEvent(DropMethod method, @Nullable DropTargetEvent e, T value);
 
 		default <R> TypedDropHandler<R> map(Function<? super R, ? extends T> mapper) {
 			return new MappedTypedDropHandler<R, T>(this, mapper);
@@ -225,6 +230,21 @@ public Listener(ImmutableMap<Transfer, Handler> map) {
 			transfers = map.keySet().toArray(new Transfer[map.size()]);
 		}
 
+		public void pasteFromClipboard() {
+			Clipboard clipboard = new Clipboard(SwtMisc.assertUI());
+			try {
+				for (Transfer transfer : transfers) {
+					Object data = clipboard.getContents(transfer);
+					if (data != null) {
+						handlers.get(transfer).handler.onEvent(DropMethod.drop, null, data);
+						break;
+					}
+				}
+			} finally {
+				clipboard.dispose();
+			}
+		}
+
 		public Transfer[] transferArray() {
 			return Arrays.copyOf(transfers, transfers.length);
 		}
@@ -279,16 +299,21 @@ public AbstractTypedDropHandler(DndOp operation) {
 		}
 
 		@Override
-		public void onEvent(DropMethod method, DropTargetEvent e, T value) {
+		public void onEvent(DropMethod method, @Nullable DropTargetEvent e, T value) {
 			if (method == DropMethod.dragLeave) {
 				return;
 			} else {
 				if (value == null) {
 					// this means that we don't know what the data is yet
-					operation.trySetDetail(e);
+					if (e != null) {
+						operation.trySetDetail(e);
+					}
 				} else if (accept(value)) {
-					if (operation.trySetDetail(e) && method == DropMethod.drop) {
-						drop(e, value, e.detail == DND.DROP_MOVE);
+					if (e == null) {
+						drop(null, value, false);
+					} else if (operation.trySetDetail(e) && method == DropMethod.drop) {
+						boolean moved = e.detail == DND.DROP_MOVE;
+						drop(e, value, moved);
 					}
 				}
 			}

durian-swt/src/test/java/com/diffplug/common/swt/dnd/StructuredDndMappingTest.java

@@ -15,10 +15,12 @@
  */
 package com.diffplug.common.swt.dnd;
 
+import java.util.function.BiConsumer;
 import java.util.function.Consumer;
 import java.util.function.Function;
 
 import org.eclipse.swt.SWT;
+import org.eclipse.swt.widgets.Button;
 import org.eclipse.swt.widgets.Composite;
 import org.eclipse.swt.widgets.Group;
 import org.eclipse.swt.widgets.Label;
@@ -75,6 +77,18 @@ <T> void addGroup(String name, T value, Playground<T> coat) {
 					dndCtl.setText("Drag and drop");
 					drag.applyTo(dndCtl, DndOp.COPY);
 					drop.applyTo(dndCtl);
+
+					Composite btnCmp = new Composite(txtGrp, SWT.NONE);
+					Layouts.setGridData(btnCmp).grabHorizontal();
+					Layouts.setGrid(btnCmp).margin(0).numColumns(2);
+					BiConsumer<String, Runnable> addBtn = (lbl, toRun) -> {
+						Button btn = new Button(btnCmp, SWT.PUSH | SWT.FLAT);
+						Layouts.setGridData(btn).grabHorizontal();
+						btn.setText(lbl);
+						btn.addListener(SWT.Selection, e -> toRun.run());
+					};
+					addBtn.accept("Copy", () -> drag.getListener().copyToClipboard());
+					addBtn.accept("Paste", () -> drop.getListener().pasteFromClipboard());
 				}
 			}
 			Adder adder = new Adder();